The gaming industry has expanded significantly in terms of the technology and variety of games, as well as the venues for the games. The gaming industry uses various forms of physical and electronic tokens, cards, chips, etc. as monetary units and playing objects. In addition, the technology now bridges conventional playing objects like chips, coins and cards in conventional venues to encompass the digital realm including electronic gaming machines, on-line gaming, electronic monetary units, etc.
Just as the technology used in gambling and casinos has diversified and become integrated with digital systems, so has the technology available to pirates. Pirates can cheat in new and various ways, from making counterfeit monetary tokens to faking playing objects like playing cards and dice.
The use of machine readable embedded data in gaming system offers a variety of ways to combat cheating as well as enhance the gaming experience. Steganographic techniques, such as digital watermarking, enable playing objects and monetary tokens to be authenticated and enhanced. Other forms of machine readable codes can be used in conjunction with digital watermarks for these applications as detailed in this document.
Digital watermarking is a process for modifying physical or electronic media to embed a hidden machine-readable code into the media. The media may be modified such that the embedded code is imperceptible or nearly imperceptible to the user, yet may be detected through an automated detection process. Most commonly, digital watermarking is applied to media signals such as images, audio signals, and video signals. However, it may also be applied to other types of media objects, including documents (e.g., through line, word or character shifting), software, multi-dimensional graphics models, and surface textures of objects.
Digital watermarking systems typically have two primary components: an encoder that embeds the watermark in a host media signal, and a decoder that detects and reads the embedded watermark from a signal suspected of containing a watermark (a suspect signal). The encoder embeds a watermark by subtly altering the host media signal. The reading component analyzes a suspect signal to detect whether a watermark is present. In applications where the watermark encodes information, the reader extracts this information from the detected watermark.
Several particular watermarking techniques have been developed. The reader is presumed to be familiar with the literature in this field. Particular techniques for embedding and detecting imperceptible watermarks in media signals are detailed in the assignee's co-pending application Ser. No. 09/503,881 and U.S. Pat. No. 6,122,403, which are hereby incorporated by reference.
Further features will become apparent with reference to the following detailed description and accompanying drawings.